Electronic oscillators are used in a variety of electronic circuits. Voltage controlled oscillators (VCOs) are type of electronic oscillator. A VCO has a voltage input that controls the oscillation frequency. An inductor-capacitor (LC) VCO is a VCO that includes a frequency-selective resonance tank including an inductor and a capacitor.
It is often desirable to tune the oscillator to a particular oscillation frequency. The oscillation frequency of an LC VCO is known to be tunable through means such as control voltage adjusting variable capacitors (varactors), or via switchable capacitors. However, the overall oscillation frequency tuning range (FTR) of existing oscillators is limited. LC VCOs are known to have very low phase noise but a narrow FTR.
Improvements in tunable oscillators are desired, including in their overall oscillation frequency tuning ranges.
The above information is presented as background information only to assist with an understanding of the present disclosure. No assertion or admission is made as to whether any of the above might be applicable as prior art with regard to the present disclosure.